Journal of Cement Based Composites (CEBACOM)

Ramesh Gupta Amoli Hassan Saravana Kumar

Due to the environmental impact of sulphates and salts on concrete and the significant reduction in concrete strength, extensive research has been carried out to reinforce concrete against these types of attacks. The results show that the use of coal ash increases Concrete quality is counteracting the attack of sulfates. The sulfates include calcium sulfate, sodium sulfate, magnesium sulfate, and the like. Sulfate attack in tropical coastal areas with hot and humid weather causes very severe damage. One can refer to ash of cane sugar syrup (bagasse) as one of the most suitable alternatives for cement in concrete. Other materials that can be considered for preventing attack of sulfates include concrete containing carbon nanotubes and shells ash pozzolan Rice. Use of 80% cement, carbon nanotubes and 15% zirconium rice ash in concrete structure improve concrete performance against sulfate attack and corrosion resistance. According to the results of concrete containing nanotube Carbon and pozzolan rice husk has the highest corrosion resistance in the range of 20 to 25 minutes. Do not.

https://doi.org/10.36937/cebacom.2020.002.001

İlker Bekir TOPÇU Erdi AKKAN Tayfun UYGUNOĞLU Kardelen ÇALIŞKAN

Many studies have been carried out on the problems of civil engineering with the change of human problems today and in the past. These studies contributed to the development of concrete technology. Concrete is an important building material consisting of mixing aggregate, cement and water with or without chemical and mineral additives since the first day of use. Concrete technology has made great progress and continues. With developing concrete technology, self-cleaning concretes have emerged. Many studies have been conducted on self-cleaning concretes by researchers. This article reviews the research published on self-cleaning concretes and presents its role in reducing environmental pollution and its place in future engineering studies.When we look at the studies on self-cleaning concretes that emerged as a result of the developments in concrete technology, it is seen that the developments have progressed considerably. Contemporary civil engineering has provided a highly effective solution for the solution of modern problems. Environmentally friendly building materials will fulfil their duty in reducing air pollution, one of the biggest problems of our time. Self-cleaning buildings and roads that reduce pollution may sound like futuristic ideas, but it is not far away to encounter these structures more widely in our country and our world.

https://doi.org/10.36937/cebacom.2020.002.002

Abdulhameed Umar Abubakar Maimuna Salisu Tabra

In this study, a neural network based model available in Weka Algorithms, was utilized to test the predictive capacity of compressive strength in high strength concrete (HSC) with steel fiber addition. Fiber addition levels ranged from 0.19 – 2.0% were utilized obtained from literature with a total of 192 instances (datasets) and 10 attributes. To test the performance of the algorithm, a 10 – fold cross-validation method was used to assess the effectiveness which was later compared with full training sets. Also, seven learning schemes were utilized to determine the optimum using percentage split. Results generated from the model include correlation coefficient, mean absolute error, root mean squared error, and relative absolute error. It was observed a good correlation coefficient was obtained which was close to unity at 70-30 and 80-20% of training to testing, and significant reduction in the associated errors were observed. Results for coefficient of determination are also presented and follow the same trend observed in the percentage split results. Time taken to generate the model was much shorter an indication of efficiency.

https://doi.org/10.36937/cebacom.2020.002.003

Engin Yener Cemal Karaaslan

The effects of curing regimes varying combinations of temperatures (ambient, 60°C, 75°C, 90°C, 105°C) and durations (4h, 8h, 24h, 48h, 96h, 168h) on the performance of fly ash added pumice based geopolymer pastes were investigated in this study. The precursor raw material consists of 70% pumice dust and 30% fly ash (FA). Alkali activator was prepared by mixing 10M sodium hydroxide (SH) solution and liquid sodium silicate (SS) in the ratio of SS/SH=2. Activator to precursor ratio was fixed as 0.45. Compressive strengths were determined at the 28 days of age as well as after exposure 5 wetting-drying (w-d) cycles. In addition, Fourier Transform Infrared Spectroscopy (FTIR) tests were conducted on the fresh and hardened geopolymer pastes in order to examine the effect of curing conditions to the structural changes and reaction products. The results show that in the case of 60 °C and 75 °C, the strength of the w-d conditioned samples increased steadily as the curing time increased. However, longer curing times of more than 24 hours are not beneficial for high curing temperatures (90 °C and 105 °C). The maximum strength after the w-d cycles is obtained for the curing conditions of 60°C/168h (74.4 MPa). Also, FTIR analysis confirmed that the hardened geopolymer paste transformed into a more coordinated structure and soluble carbonate compounds were reduced at 60 °C and 168 hours curing condition.

https://doi.org/10.36937/cebacom.2020.002.004